Ant offers some XML features like the xslt task, which transforms XML files into other files. But unfortunately, with Ant you can’t make simple XPath Queries on a specific XML file.

Luckily, there is a nice open source solution called XmlTask, which offers many possibilities to work with XML files.

1. Download the latest version of XmlTask from http://xmltask.sf.net
2. Create a task definition in Ant

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   <taskdef name="xmltask" classname="com.oopsconsultancy.xmltask.ant.XmlTask" classpath="./xmltask-v1.15.1.jar" />

3. Use it with the <xmltask> definition
   
   For example, read out the number of a specific node in the XML file:

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   <xmltask source="someFile.xml"> <copy path="count(//aNode)" property="numberOfNodes" /> </xmltask>

   Or change an attribute:

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   <xmltask source="someFile.xml" dest="toAnotherFile.xml"> <attr path="//aNode[1]" attr="enabled" value="true"/> </xmltask>

There are many other possibilites to work with XML files inside Ant. Check out the documentation at http://xmltask.sf.net.

There are some kind of tasks, which Ant won’t do. One of them is the loop. There is no simple way to implement a dynamic for or while loop in Ant. What do i mean with dynamic? Let me make an example. Ant reads out a number of iterations from a property file (we call it the number x) and should perform a loop x-times to call another Ant task. And this can only hardly be done with Ant.

But fortunately, there is Groovy. Groovy is a scripting language, which runs in a Java Virtual Machine. And because of that, it can be easily integrated with Ant.

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In some cases, ANT has it’s limitations. For example, it is not really easy to create an if-else structure or a for-loop. For this reason, a few people started long time ago the Ant-Contrib project. Just download it and put the jar file in the lib folder of the project. Then, just at following line to the build file:

<taskdef resource="net/sf/antcontrib/antcontrib.properties"></taskdef>

Now, you can start using constructs like if, foreach and combine these tasks with usual ANT tasks. Here a little example:

with antcontrib:

<target name="theultimateconditionmachine">
  <if>
    <equals arg1="${foo}" arg2="bar" />
    <then>
      <echo message="property foo is bar" />
    </then>
    <else>
      <echo message="property foo is not bar" />
    </else>
  </if>
</target>

without antcontrib:
if you want to perform the same task with ant, you need to create 4 (!) ant targets:

<target name="noway">
  <antcall target="conditionIf"/>
  <antcall target="conditionElse"/>
</target>
 
<target name="conditionDef">
  <condition property="conditionIsTrue">
    <equals arg1="${foo}" arg2="bar"/>
  </condition>
</target>
 
<target name="conditionIf" depends="conditionDef" if="conditionIsTrue">
  <echo message="property foo is bar"/>
</target>
 
<target name="conditionElse" depends="conditionDef" unless="conditionIsTrue">
  <echo message="property foo is not bar"/>
</target>